When wireless communication apparatuses that carry out wireless communication by a plurality of wireless communication techniques using neighboring frequencies coexist inside a vehicle or the like, communication interference, that is, radio waves the wireless communication apparatuses use become noise to each other, thereby deteriorating communication quality.
In particular, both a wireless LAN (Local Area Network) and Bluetooth (registered trademark: not referred to from now on) utilize 2.4 GHz band frequency as their frequency channels. Accordingly, the communication interference mentioned above are likely to occur.
A wireless communication apparatus described in a Patent Document 1 comprises wireless communication units with different wireless communication techniques using the same frequency band such as a wireless LAN and Bluetooth. The wireless communication apparatus assigns a use frequency channel to each wireless communication unit in such a manner that the channels do not overlap, thereby reducing communication interference to each other.
In addition, a Patent Document 2 discloses a wireless communication apparatus that appropriately detects or avoids communication interference according to statistical information about a communication state of an actual wireless LAN.
On the other hand, a mobile station described in a Patent Document 3 has a function of deciding on whether it is located indoors or outdoors. For example, it decides on whether the mobile station is located indoors or outdoors according to the distance covered by the mobile station estimated from the received power of the positioning signal transmitted from GPS (Global Positioning System) satellites and from position information contained in the positioning signal. Furthermore, the mobile station of the Patent Document 3 makes a similar decision according to position information and map information from base stations of a mobile phone network.